Wafer Handler Method and System

ABSTRACT

Systems and methods for handling wafers include retrieving a first wafer from a wafer cassette using a first arm, transferring the first wafer from the first transfer arm to a second arm, delivering the first wafer for processing to a process chamber using the second arm, removing the first wafer from the process chamber using the first arm, and returning the first wafer to the cassette using the first arm. The systems and methods can include retrieving a first wafer from a wafer cassette using a first arm, delivering the first wafer for processing to a process chamber using the first arm, removing a processed wafer from the process chamber using a second arm, returning the processed wafer to the cassette using the second arm, and iteratively retrieving, delivering, removing and returning wafers from the cassette while alternating arms between iterations.

RELATED APPLICATIONS

This application is a divisional of, claims priority to, andincorporates by reference, the entire disclosure of U.S. patentapplication Ser. No. 10/687,023, filed on Oct. 16, 2003.

BACKGROUND

1. Field

The disclosed methods and systems relate generally to semiconductorprocessing, and more particularly to wafer handling methods and systems.

2. Description of Relevant Art

Some challenges of semiconductor manufacturing include providing amanufacturing process that produces reduced process defects withincreased process throughput. These manufacturing concerns can also bebalanced with other requirements that include a need for reducedcontamination.

FIG. 18 provides one semiconductor wafer processing system 10 where, forexample, a cassette of semiconductor wafers (“wafers”) can be presentedto left and right load locks 12, 14 to allow wafer transfers to aprocessing chamber 16 such as, for example, an ion implantation chamber.The load locks 12, 14 can be understood to be an interface between aloading station and the processing chamber 16. Because the wafers can beloaded from a loading station that may often be at atmospheric pressure,once the wafers are presented to the load locks 12, 14, the lock loads12, 14 can be isolated from the loading station and the processingchamber 16. A load lock vacuum pump, for example, can thus reduce theload lock pressure, or “evacuate” a respective load lock 12, 14, inaccordance with, or to be consistent with the processing chamberpressure.

Wafers from the cassettes in the left and right load locks 12, 14 can beprocessed in turn, alternating between left and right load locks 12, 14.Accordingly, in a system according to FIG. 18, the left and right loadlocks 12, 14 can be substantially simultaneously evacuated andthereafter opened or otherwise interfaced to the processing chamber 16.For exemplary purposes, a left arm 18 can retrieve a wafer from the leftload lock cassette, and present the retrieved wafer to a left orienter20 that can locate a wafer notch to align the wafer center with theorienter axis of centricity. The left arm 18 can thereafter deliver thewafer to a platen 22 in the process chamber 16, and thereafter, the leftarm 18 can be displaced to allow wafer processing. Once the wafer isprocessed, the left arm 18 can deliver the wafer from the platen 22 tothe left orienter 20 and hence to the left load lock cassette. As FIG.18 indicates, a wafer from the right load lock cassette can be retrievedby a right robot 24 and placed on a right orienter 26 before beingdelivered to the platen 22 for processing. Such wafer can also bereturned to the right load lock 14 after processing is complete. Asprovided previously herein, throughput for a system according to FIG. 18can be improved by coordinating the alternating delivery of wafers fromthe left and right load lock cassettes to reduce delay betweendeliveries to the platen 22.

For a system according to FIG. 18, once the wafers from the left andright load lock cassettes are processed and returned to the load lockcassettes, the load locks 12, 14 can be isolated from the processingchamber 16 to allow a substantially simultaneous venting of the loadlocks 12, 14 and a return to a pressure according to, or otherwiseconsistent with the loading station pressure. The interfaces between therespective load locks 12, 14 and the loading station(s) can then beopened to allow transfer of the left and right cassettes in accordancewith a processing methodology.

Batch vacuum load locks such as those according to FIG. 18 canexperience poor cycle time because the larger volume of a batch loadlock can present a longer evacuation time, during which wafers are beingprocessed from neither the left nor right load locks 12, 14.

SUMMARY

The systems and methods disclosed herein can include wafer handlingmethods and systems for retrieving wafers from a storage position,delivering the wafers to a process chamber and returning the processedwafers to the storage position a method for handling wafers can includeretrieving a first wafer from a wafer cassette using a first arm,transferring the first wafer from the first arm to a second arm,delivering the first wafer for processing using the second arm so as togenerate a processed wafer, removing the processed wafer from processingusing the first arm and returning the processed wafer to the storageposition using the first arm.

The method can include delivering the first wafer using the second armwhile retrieving a next wafer from the storage position using the firstarm. The first wafer can be oriented prior to being transferred. Themethod can further include processing the first wafer in the processchamber, wherein processing can include performing photoresist, dryetch, ion implantation, chemical deposition, and/or diffusion.Processing can also include orienting the next wafer and/or transferringthe next wafer from the first arm to the second arm.

The storage position can be a wafer cassette and retrieving the firstwafer or returning the processed wafer can include indexing thecassette.

Returning the processed wafer using the first arm can include deliveringthe next wafer for processing using the second arm or placing the secondarm in a standby position. Transferring the wafers between arms caninclude aligning the first arm and the second arm to facilitate thetransfer. Transferring can include controlling an orienter to transferthe first wafer from the first arm to the second arm.

In another embodiment a method for handling wafers can includeretrieving a first wafer from a wafer cassette using a first arm,transferring the first wafer from the first arm to a second arm,delivering the first wafer for processing using the second arm whileretrieving a distinct next wafer from the wafer cassette using the firstarm, processing the first wafer to generate a processed wafer, whiletransferring the next wafer from the first arm to the second arm,removing the processed wafer from processing using the first arm anddelivering the next wafer for processing using the second arm whilereturning the processed wafer to the cassette using the first arm.

The method can include retrieving a distinct next wafer from thecassette using the first arm while processing the next wafer, anditeratively performing the processing, removing, and delivering.Processing can include performing photoresist, dry etch, ionimplantation, chemical deposition, and/or diffusion. Transferring caninclude controlling an orienter to transfer the first wafer between thefirst arm and the second arm. Retrieving can include indexing thecartridge.

In a further embodiment, a method for processing wafers from two or moreload locks can include processing wafers from a first wafer cassette ina first load lock, where the wafers are delivered for processing fromthe first wafer cassette using two arms, performing load lock processingfor at least a second load lock to obtain a processed load lock whileprocessing the wafers of the first wafer cassette, completing theprocessing of the first wafer cassette and processing wafers from asecond wafer cassette in the processed load lock, where the wafers aredelivered for processing from the second wafer cassette using two arms.The method can include performing load lock processing of the first loadlock upon completion of processing of the first wafer cassette.Additionally, the method can include performing load lock processing ofthe first load lock upon completion of processing of the first wafercassette, completing the processing of the second wafer cassette andprocessing wafers from a replacement wafer cassette in the first loadlock, where the wafers are delivered for processing from the replacementwafer cassette using two arms. Performing load lock processing caninclude evacuating, venting, isolation, cassette removal, cassettereplacement, cassette installation, and/or lock valve control.

In one embodiment a system for handling wafers can include a first armfor handling wafers, a distinct second arm for handling wafers, a firstcassette of wafers and a wafer processing system.

The wafers can be delivered to the processing system from the firstcassette using the first arm and the second arm, and the delivery caninclude individually retrieving a first wafer from the cassette usingthe first arm, transferring the first wafer from the first arm to thesecond arm, delivering the first wafer for processing by the waferprocessing system using the second arm, processing the first wafer togenerate a processed wafer, while retrieving a next wafer from thecassette using the first arm, transferring the next wafer to the secondarm, removing the processed wafer using the first arm and delivering thenext wafer for processing using the second arm, processing the nextwafer to generate a processed wafer while returning the processed waferto the cassette and iteratively performing the processing, transferring,removing, and processing to process the wafers in the cassette.

The system can include a first load lock for the first cassette, anorienter for orienting the wafers before processing and transferring thewafers between the first arm and the second arm and a platen forretrieving wafers from the second arm for delivering the wafers, andtransferring processed wafers to the first arm for removing theprocessed wafers.

In a further embodiment a method for handling wafers can includeretrieving a next wafer from a selected cassette using a first arm,transferring the next wafer to a second arm, removing a processed waferfrom a process system using the first arm, delivering the next wafer tothe process system using the second arm and returning the processedwafer to the selected cassette using the first arm.

In one aspect, the method can iteratively return to retrieving.Transferring can include using an orienter to transfer the next wafer.The processed wafer can be oriented before returning the processed waferand a cassette can be selected prior to retrieving. The method candetermine whether unprocessed wafers remain in the selected cassette,and, based on the determination, can select a new cassette anditeratively return to retrieving, and/or perform load lock processingassociated with the processed cassette.

In one embodiment, a method for handling wafers can include retrieving anext wafer from a storage position using a first arm, removing aprocessed wafer from processing using a second arm, delivering the nextwafer for processing, returning the processed wafer to the storageposition, and iteratively performing the retrieving, delivering andreturning while alternating using the first arm and the second armbetween iterations. Returning can include returning while processing thenext wafer in a process chamber. Processing can include performing atleast one of photoresist, dry etch, ion implantation, chemicaldeposition, and diffusion. The method can include orienting the nextwafer prior to delivering the next wafer. The storage position can be awafer cassette, and retrieving and returning the processed wafer to thecassette can include indexing the cassette. Returning the processedwafer to the storage position using the second arm can include placingthe first arm in a standby position.

In one embodiment, a method for handling wafers can include retrieving afirst wafer from a wafer cassette using a first arm while removing aprocessed wafer from processing using a second arm, delivering the firstwafer for processing, returning the processed wafer to the wafercassette while processing the first wafer to generate a processed wafer,retrieving a next wafer from the wafer cassette using the second armwhile removing the processed wafer from processing using the first arm,delivering the next wafer for processing, returning the processed waferto the wafer cassette while processing the next wafer to generate a nextprocessed wafer, and iteratively performing the retrieving, deliveringand returning while alternating using the first arm and the second armbetween iterations. The method can include orienting the first waferprior to delivering the first wafer, and orienting the next wafer priorto delivering the next wafer. Retrieving can include indexing thecassette. Delivering the first and next wafers can include processingthe first and next wafers in a process chamber and processing caninclude performing at least one of photoresist, dry etch, ionimplantation, chemical deposition, and diffusion.

In one embodiment, a system for handling wafers can include a first armfor handling wafers, a distinct second arm for handling wafers, a firstcassette of wafers, and a wafer processing system, where wafers aredelivered to the processing system from the first cassette using thefirst arm and the second arm, and where the delivery includes,individually retrieving a first wafer from the cassette using the firstarm, delivering the first wafer for processing by the wafer processingsystem using the first arm, returning a processed wafer to the cassetteusing a second arm while processing the first wafer to generate aprocessed wafer, retrieving a next wafer from the cassette using thesecond arm, removing the processed wafer using the first arm anddelivering the next wafer for processing using the second arm,processing the next wafer to generate a processed wafer while returningthe processed wafer to the cassette, and iteratively performing theretrieving, delivering, returning, retrieving, removing, and processingto process the wafers in the cassette.

The system can include a first load lock for the first cassette and anorienter for orienting the wafers before processing. The system caninclude a platen for retrieving wafers from the first and second armsfor processing the wafers, and transferring processed wafers to thefirst and second arms for removing the processed wafers. The system caninclude at least one carriage for moving the first and second armsrelative to the cassette for returning and retrieving wafers from thecassette.

Other objects and advantages will become apparent hereinafter in view ofthe specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a system that includes a first and second arm forhandling wafers;

FIG. 2 illustrates a first arm in a load lock retrieval position, with asecond arm in a standby position;

FIG. 3 illustrates the first arm in an orienter position, with thesecond arm in a standby position;

FIG. 4 illustrates the first and second arms in the orienter positionsfor a delivery of an initial wafer for processing;

FIG. 5 illustrates the first arm in a load lock retrieval position, withthe second arm in a process position;

FIG. 6 illustrates the first arm in the orienter position, with thesecond arm in a standby position;

FIG. 7 illustrates the first and second arms in the orienter positionsfor a delivery of a non-initial wafer for processing;

FIG. 8 illustrates the first arm in a platen retrieval position, withthe second arm in a process position;

FIG. 9 illustrates the first arm in an orienter position, with thesecond arm in a process position;

FIG. 10 illustrates the first arm in a load lock delivery position, withthe second arm in a standby position;

FIG. 11 illustrates the first arm in an orienter position, with thesecond arm in a standby position;

FIG. 12 illustrates the first arm in a load lock retrieval position,with the second arm in a standby position;

FIG. 13 illustrates the first arm in an orienter position, with thesecond arm in a standby position;

FIG. 14 illustrates the first and second arms in the orienter positionsfor a delivery of a non-initial wafer for processing;

FIG. 15 illustrates a block diagram for one disclosed system and method;

FIGS. 16A- 16C illustrate an embodiment of a system that includes afirst and second arm for handling wafers;

FIG. 17 illustrates a block diagram for another disclosed system andmethod; and,

FIG. 18 illustrates a prior art system.

DESCRIPTION

To provide an overall understanding, certain illustrative embodimentswill now be described; however, it will be understood by one of ordinaryskill in the art that the systems and methods described herein can beadapted and modified to provide systems and methods for other suitableapplications and that other additions and modifications can be madewithout departing from the scope of the systems and methods describedherein.

Unless otherwise specified, the illustrated embodiments can beunderstood as providing exemplary features of varying detail of certainembodiments, and therefore, unless otherwise specified, features,components, modules, and/or aspects of the illustrations can beotherwise combined, separated, interchanged, and/or rearranged withoutdeparting from the disclosed systems or methods. Additionally, theshapes and sizes of components are also exemplary and unless otherwisespecified, can be altered without affecting the disclosed systems ormethods.

The disclosure includes wafer handling methods and systems forretrieving wafers from a wafer cassette in a load lock, delivering thewafers to a process chamber, and returning the processed wafers to thecassette. The methods and systems include a first arm and a second armthat can be coordinated to perform the retrieval, delivery, and returnof wafers to allow wafers from the same cassette and/or load lock to besequentially processed. As provided herein, sequential processing is notto be understood as implying an order of retrieval from the cassette.

Accordingly, for the disclosed methods and systems, a first arm forhandling wafers can be understood to be a robotic or other mechanical,electrical, and/or electromechanical arm that may be capable of handlingwafers as provided herein. The first arm can be of varying shape such asc-shaped, u-shaped, or another shape, and the methods and systems hereinare not limited by a type and/or shape of arm, or a method or system bywhich the arm may be controlled. The methods and systems also include asecond arm. Although the illustrated embodiments indicate that thesecond arm can be the same as the first arm, one of ordinary skill willrecognize that the first arm and the second arm can have a differentshape, structure, components, and methods, and may have a differentcontroller from the first arm, although in an embodiment where differentcontrollers may be used, such first arm and second arm controllers canbe coordinated to provide a method and system as provided herein.

Although the figures presented herein illustrate two load locks referredto as left and right load locks 12, 14, the disclosed methods andsystems are not so limited, and include methods and systems with one ormore load locks. Further, it can be understood that for the illustratedembodiments that indicate two load locks and where the methods andsystems are described relative to the left load lock 12, such methodsand systems can also be applied to the right load lock 14.

FIG. 1 shows one embodiment according to the disclosed methods andsystems for handling wafers that includes left and right load locks 12,14. As provided herein, the methods and systems will be describedrelative to the left load lock 12 with the understanding that themethods and systems can be applied to the right load lock 14. TheFigures illustrate positions that may be engaged by a first arm 18 and asecond arm 30 that can access the left load lock 12. As will be providedherein, the first arm 18 can be positioned in positions that include atleast a load lock position to allow the first arm 18 to retrieve and/orreturn a wafer from/to the cassette 32 in the left load lock 12, anorienter position to allow the first arm 18 to interface with at leastan orienter 20, and a process position to allow the first arm 18 toretrieve a wafer from a process chamber 16. Those of ordinary skill willrecognize that the methods and systems can be applied to various processsystems for delivering wafers to process chambers that perform, forexample, at least one of photoresist, dry etch, ion implantation,chemical deposition, and diffusion, although such examples are providedfor illustration and not limitation, and other processing can beperformed in the process chamber 16. Although the illustratedembodiments indicate the use of wafer cassette 32, one of ordinary skillwill recognize that other wafer storages means that that can presentwafers for retrieval from a storage position such as a load lock can beemployed and that the systems and methods described herein can beadapted for use therewith.

The second arm 30 can be positioned in positions that include at least astandby position to allow the second arm 30 to not interfere withprocessing of a wafer or with the first arm's interaction with theorienter 20, an orienter position to allow the second arm 30 tointerface with at least the orienter 20, and a process position to allowthe second arm 30 to deliver a wafer to the process chamber 16.Accordingly, based on an embodiment, a standby position and an orienterposition may be the same position for the second arm 30. One of ordinaryskill thus recognizes that unlike the other arm positions describedherein that can be based on, for example, the orienter, the load lock,and a platen, the standby position is not so defined and may include anumber of positions, including other defined positions.

It can thus be recognized that the first arm 18 and the second arm 30include orienter positions and process chamber positions, and asprovided herein, vertical transfers of wafers between the first arm 18and the second arm 30 can be performed while such arms 18, 30 may bemaintained in such positions. Accordingly, the first arm 18 and thesecond arm 30 can be arranged to allow a distance that facilitatesindependent operation when vertically aligned, while recognizing that areduced vertical distance between the first and second arms 18, 30 mayreduce processing time to transfer wafers between the same. Althoughsuch vertical distance between such arms 18, 30 can thus vary based onsystem characteristics, in one embodiment, when vertically aligned, thefirst and second arms 18, 30 can be separated by less than approximatelyfive-eights to one-half of one inch.

Returning again to FIG. 1, one of ordinary skill may recognize that thechamber 16 is shown to be enlarged to accommodate the second arm 30which may be understood to be illustrated in one of the aforementionedstandby positions. It can be understood that such enlargement of theprocess chamber 16 is optional, and in some embodiments, suchenlargement may not be necessary to accommodate one or more standbypositions for the second arm 30.

As one of ordinary skill in the art also recognizes, the cassette 32 canbe introduced to the load lock 12 via a loading station, where the loadlock can be isolated from the loading station and the process chamber 16to allow the load lock pressure to be altered according to (e.g., to beconsistent with) the pressure in the process chamber 16. For example, avacuum or other pressure device can lower the pressure in the load lock.Once the load lock pressure is sufficiently altered, a valve 34 or othermechanism can be altered to allow at least the first arm 18 from theprocess chamber 16 to access the load lock 12, and specifically, wafersincluded in the cassette 32.

It may thus be understood that the cassette can include one or morewafers, but in an illustrative example, can include approximatelytwenty-five to fifty wafers. Referring to FIG. 2, the first arm 18 canthus be configured to access wafers in the cassette 32 to allow thefirst arm 18 to retrieve a wafer. Those of ordinary skill will recognizethat the cassette 32 may be controlled and/or indexed and such controland/or indexing may be coordinated with the operation of the first arm18 to facilitate retrieval of a wafer. FIG. 2 illustrates the second arm30 in a standby mode, and although such may be the case for an initialwafer retrieved from a cassette 32, as provided herein, for subsequentwafer retrievals, the second arm 30 may not be positioned in a standbymode. Furthermore, the second arm 30 may be in another “standby”position, such as in the orienter position.

FIG. 3 presents the first arm 18 in the orienter position to allow theretrieved wafer to be oriented for processing. Those of ordinary skillin the art will recognize that the orienter 20 can be controlled orotherwise operated in the illustrated systems to allow for the orienter20 to be vertically aligned with at least the first arm 18 when thefirst arm 18 is in the orienter position, and accordingly, the orienter20 can be adjusted as needed to interface with the first arm 18 to alloworientation of the wafer. At such time, the second arm 30 may be in astandby position, although as provided herein, the second arm 30 may bein another position such as the orienter position.

Referring to FIG. 4, the orienter 20 can facilitate a transfer of thewafer from the first arm 18 to the second arm 30, where such first andsecond arms 18, 30 can be vertically aligned to allow such transfer bythe orienter 20. Accordingly, the illustrated orienter 20 can becontrolled for vertical displacement. It may be recognized that thevertical alignment of the first and second arms 18, 20 can be performedat a time prior to the transfer of the wafer by the orienter 20, and thedisclosed methods and systems are not limited by the moment and/ortiming of the alignment unless otherwise provided herein. Accordingly,the alignment may occur during orientation, or the alignment may occurprior to wafer orientation.

FIG. 5 shows a delivery of the wafer by the second arm 30 forprocessing, where in the illustrated systems, the processing area can bea platen 22. As FIG. 5 also illustrates, as the second arm 30 is in theprocess position, the first arm 18 can be in a load lock position toretrieve a second (or “next”) wafer from the cassette 32. Accordingly,the cassette 32 can be controlled or indexed in association with thefirst arm 18 to allow the first arm's 18 retrieval of the next wafer.

For the discussion herein, the “next” wafer can be understood to the benext wafer retrieved for processing, and will be referred to as the“next” wafer until the wafer is processed, whereupon such wafer can bereferred to as the processed wafer.

FIG. 6 indicates the first arm 18 in an orienter position while thesecond arm 30 resides in an arbitrary standby position. As FIG. 6 alsoindicates, the first wafer can be processed 36 in the process chamber 16while the next wafer may be oriented by orienter 20. Further, the secondarm 30 may be in an alternate (e.g., orienter) position, as shown inFIG. 7. FIG. 7 also accordingly indicates, similar to FIG. 4, a transferof the next wafer from the first arm 18 to the second arm 30 where suchtransfer is facilitated by the orienter 20 as previously provided hereinwith respect to FIG. 4. Depending on the process system, the first wafermay be processed 30 during such transfer of the second wafer from firstarm 18 to second arm 30.

FIG. 8 indicates a movement of the first arm 18 and the second arm 30 tothe process position after a transfer of the next wafer to the secondarm 30 and after processing of the first wafer (now the “processed”wafer). Although FIG. 8 indicates a simultaneous movement of the firstand second arms 18, 30 from an orienter position to a process position,such movement can be non-simultaneous. In a configuration according toFIG. 8, the first or processed wafer can be transferred from and/or bythe processing system to the first arm 18 and the next wafer can bedelivered to the processing system by the second arm 30. Suchfirst/processed and next wafer transfers between the processing system,first arm 18, and second arm 30 can be coordinated to eliminateinterface between the processed and next wafers. Accordingly, forexample, in an ion implantation system, a platen 22 can be controlled orotherwise employed to transfer the first wafer to the first arm 18 forremoval from processing, while thereafter, the platen 22 can retrievethe next wafer from the second arm 30.

FIG. 9 indicates that once the platen 22 transfers the first orprocessed wafer to the first arm 18, the first arm 18 can return to anorienter position while the second arm 30 can remain in the processposition to allow the platen 22 to transfer the next wafer from thesecond arm 30. The first or processed wafer can thus also be returned tothe cassette 32 in the left load lock 12, as shown by FIG. 10. Suchillustration thus indicates that the cassette 32 can be controlled orindexed to facilitate a return of the first or processed wafer. FIG. 10also shows that upon delivery of the next wafer to the platen 22, thesecond arm 30 can return to a standby or other position that is not theprocess position.

FIG. 11 illustrates the next wafer being processed 36 in the processchamber 16 while the first arm 18 is in the orienter position, orretracted from the cassette 32, and the second arm 30 is in a standbyposition. Accordingly, the FIG. 11 cassette 32 can be controlled orindexed to facilitate a third wafer retrieval, which can now be referredto as the “next” wafer, where such retrieval of a third or next wafer bythe first arm 18 is illustrated in FIG. 12. Such third or next waferretrieval from the cassette 32 in the load lock 12 can be performedduring processing 36 of the second wafer (which is now the “processed”wafer), where the first arm can return to an orienter position as shownin FIG. 13 to interface the third or next wafer with the orienter 20,and to thereafter facilitate a transfer of the third or next wafer bythe orienter 20, where such transfer is from the first arm 18 to thesecond arm 30 as provided previously herein with respect to FIGS. 4 and7, and as shown in FIG. 14, where such transfer can occur duringprocessing 36 of the second or processed wafer.

One of ordinary skill will thus recognize that the methods of FIGS. 8through 14 can be repeated in an iterative manner to sequentiallyprocess wafers in the cassette 32 in the left load lock 12, where asprovided previously herein, sequential processing does not imply anorder of processing. Accordingly, references to the next and processedwafers can continue as wafers are retrieved and processed, with wafersbeing referred to as the “next” wafer from retrieval from the cassette32 through a processing 36 in the process chamber 16, whereupon suchprocessing causes the “next” wafer to be referred to as the “processed”wafer.

The methods and systems are thus not specific to a certain waferretrieval sequence, and such sequence can be based on a given system.Further, some embodiments may not process all wafers in the cassette.Additionally, although the illustrated methods and systems indicate thatthe first arm 18 was vertically displaced in a certain directionrelative to the second arm 30, other embodiments may reverse theconfiguration. Similarly, other embodiments may provide for non-verticalalignment of arms 18, 30, orienter 20, and/or platen 22.

When a cassette from, for example, the left load lock 12 of FIG. 14, isprocessed, the methods and systems described herein can be applied tothe right load lock 14, and/or another load lock. During a processingof, for example, the right load lock 14 as provided herein with respectto FIGS. 1-14, the left load lock 12 can be isolated from the processingchamber, pressurized in accordance with the loading station, and thecassette 32 can be removed from the load lock 12. Further, a newcassette 32 can be loaded from the loading station to the left load lock12, the left load lock 12 can be isolated, the left load lock can beevacuated in accordance with the processing chamber 16, and the loadlock valve 34 can be opened to facilitate processing of the left loadlock cassette 32 upon completion of the right load lock cassette.Accordingly, the methods and systems allow processing of one cassette ina first load lock while another cassette is load lock-processed (e.g.,isolated from processing chamber, vented, interchanged, evacuated, valveopened, etc.) in a second load lock.

Further, it can be recognized that while the wafer processing describedrelative to FIGS. 1-14 was performed on the cassette wafers in the leftload lock 12, the right load lock 14 could be performing load lockprocessing, including for example, isolation from the processing chamber16, venting the right load lock 12, changing and/or replacing the rightload lock cassette, isolating the right load lock 12, evacuating theright load lock 12, opening the load lock valve to expose the right loadlock to the processing chamber 16, etc. Also, although not otherwiseshown in the illustrations, one of ordinary skill thus can recognizethat the methods and systems include first and second arms to processthe wafers from the right load lock cassette, where such first andsecond arms can be the same as or different from the first and secondarms 18, 30 for processing the left load lock cassette. Accordingly,some embodiments can use a single set of first and second arms 18, 30 toaccess and/or process different load locks, while some embodiments mayassociate different first and second arms for processing different loadlocks.

FIG. 15 provides one illustration of a disclosed system and method. Asshown in FIG. 15, a first wafer can be retrieved from a cassette by thefirst arm 100, oriented 102, transferred to the second arm 104, anddelivered for processing using the second arm 106. While the first waferis being processed 108, a second or “next” wafer can be retrieved fromthe cassette using the first arm 110, oriented 112, and transferred tothe second arm 114. The first wafer, now the processed wafer, can beremoved from processing using the first arm 116 to allow the second armto deliver the next wafer for processing 118. While the next wafer isprocessed 120, the processed wafer can be returned to the cassette usingthe first arm 122, and based on whether unprocessed wafers remain in thecassette 124, the first arm can retrieve a “next” wafer from thecassette 126, orient the next wafer 112, and transfer the next waferfrom the first arm to the second arm 114. Such processing can continueaccording to FIG. 15 until a desired number of wafers in the cassetteare processed 124. When the cassette does not include wafers for whichprocessing is desired 124, a next load lock that includes a cassette ofat least one unprocessed wafer can be selected 128, and processing 100can continue on such next load lock cassette as provided in FIG. 15.Further, load lock processing can be performed 130 on the load lock thatcontains the processed wafers, where such load lock processing caninclude isolating the load lock, venting, removing a cassette, replacinga cassette, inserting a cassette, evacuating the load lock, open theload lock valve, etc. Accordingly, those of ordinary skill willrecognize that load lock processing can be performed on one or more loadlocks while wafer processing can be performed on another load lock.Further, it can be understood herein that the methods and systemsillustrated by FIG. 15 can be performed in parallel, for example, aswafer processing 108 and 120 can be performed in parallel with nextwafer retrieval, orienting, and transferral 110-114 and 122-114,respectively.

Those of ordinary skill will also recognize that although the methodsand systems presented an embodiment where during processing of aprocessed wafer, a next wafer is retrieved, oriented, and transferredfrom the first arm to the second arm, some methods and systems mayinclude shorter processing times such that processing may not coincidecompletely with retrieval, orienting, and transferral. Accordingly, insome embodiments, processing may complete before retrieval, orienting,and transferral 110, 112, 114, while in other embodiments, processingmay not complete until after retrieval, orienting, and transferral 110,112, 114, and thus may indicate a delay until removal 116 and/or ameasurement or other means to indicate when processing is complete.

FIGS. 16A-16C, show a schematic representation of another embodimentaccording to the disclosed methods and systems for handling wafers.FIGS. 16A- 16C show portions of a wafer processing system that includesa left load lock 12 and right load lock 14. As previously providedherein, the methods and systems will be described relative to the leftload lock 12 with the understanding that the methods and systems can beapplied to the right load lock 14. The FIGS. 16A-16D illustratepositions that may be engaged by a first arm 52 and a second arm 54 thatcan access the left load lock 12. As will be provided herein, the firstand second arms 52, 54 can be positioned in positions that include atleast a load lock position to allow the first and second arms 52, 54 toretrieve and/or return a wafer from/to the cassette 32 in the left loadlock 12, an orienter position to allow the first and second arms 52, 54to interface with at least an orienter 20, and a process position toallow the first and second arms 52, 54 to place a wafer in and/orretrieve a wafer from a process chamber 16.

FIG. 16A can illustrate a first arm 52 in the orienter position to allowthe retrieved wafer to be oriented for processing. Those of ordinaryskill in the art will recognize that the orienter 20 can be controlledor otherwise operated in the illustrated systems to allow for theorienter 20 to be vertically aligned with the first and second arms 52,54 when the first and second arms 52, 54 are in the orienter position,and accordingly, the orienter 20 can be adjusted as needed to interfacewith the first and second arms 52, 54 to allow orientation of the wafer.At such time as the first arm 52 is in the orienter position, the secondarm 54 may be in the process position to retrieve a processed wafer fromplaten 22.

Referring to FIG. 16B, first arm 52 can rotate to the process positionto load the retrieved wafer onto platen 22. Second arm 54 can rotate tothe orienter position. It can be understood that clearance between firstand second arms 52, 54 can be arranged to allow a distance thatfacilitates independent operation when vertically aligned, whilerecognizing that a reduced vertical distance between the first andsecond arms 52, 54 may reduce processing time to transfer wafers betweenthe first and second arms 52, 54 and the orienter 20 and the platen 22,as well as time to index wafer cassette 32. Although such verticaldistance between such arms 52, 54 can thus vary based on systemcharacteristics, in one embodiment, when vertically aligned, the firstand second arms 52, 54 can be separated by less than approximatelyfive-eights to one-half of one inch.

Once the retrieved wafer is loaded onto platen 22, first arm 52 canreturn to the orienter position, or to a standby position such that theretrieved wafer can be processed 36, as previously described, while thesecond arm 54 can return the processed wafer to the wafer cassette 32,as illustrated in FIG. 16C. As previously described, one of ordinaryskill may recognize that the chamber 16 is shown to be enlarged toaccommodate the first arm 52, which may be understood to be illustratedin one of the aforementioned standby positions. It can be understoodthat such enlargement of the process chamber 16 is optional, and in someembodiments, such enlargement may not be necessary to accommodate one ormore standby positions for the first and second arms 52, 54.

In one embodiment, shown in FIG. 16C, first and second arms 52, 54 canbe mounted on or otherwise connected to a carriage 56 that canfacilitate movement of first and second arms 52, 54 into and out of loadlock 12 for return and retrieval of wafers to and from wafer cassette32. In other embodiments, the second arm 54 can be mounted to orotherwise connected to carriage 56 and the first arm 52 can be mountedon or otherwise connected to a second carriage 58, as shown in phantomin FIG. 16C, with carriages 56, 58 being configured for separatemovement of the first and second arms 52, 54. In such embodiments, thestandby position for the first arm 52 can include the orienter position,as indicated in phantom as 52 ′in FIG. 16C, while the second arm 54 canreturn the wafer to wafer cassette 32, though it can be understood thatother of the aforementioned standby positions can be utilized. Wafercassette 32 can be indexed, such that second arm 54 can retrieve a nextwafer for processing.

The process can be repeated, as described further below with respect toFIG. 17, with the positions of the first and second arms 52, 54 beingalternated in the FIGS. 16A-16C. As shown in FIG. 17, a first wafer canbe retrieved from a cassette by the first arm 200, oriented 202, anddelivered for processing using the first arm 204. While this wafer isbeing oriented, a second or processed wafer can be removed fromprocessing using the second arm 206. The first arm can deliver the firstwafer for processing 208, while the second arm returns the next wafer tothe cassette 210. Based on whether unprocessed wafers remain in thecassette 212, the second arm can retrieve a “next” wafer from thecassette 214 for orientation of the “next” wafer 216, while the firstwafer is processing. The first wafer, now the processed wafer, can beremoved from processing using the first arm 218 to allow the second armto deliver the next wafer for processing 220. While the next wafer isprocessed 222, the processed wafer can be returned to the cassette usingthe first arm 224, and based on whether unprocessed wafers remain in thecassette 226, the first arm can retrieve a “next” wafer from thecassette 200, orient the next wafer 202, and deliver the next wafer forprocessing 204. Such processing can continue according to FIG. 17 untila desired number of wafers in the cassette are processed 212. When thecassette does not include wafers for which processing is desired 212, anext load lock that includes a cassette of at least one unprocessedwafer can be selected 228, and processing 200 can continue on such nextload lock cassette as provided in FIG. 17. Further, load lock processingcan be performed 230 on the load lock that contains the processedwafers, where such load lock processing can include isolating the loadlock, venting, removing a cassette, replacing a cassette, inserting acassette, evacuating the load lock, open the load lock valve, etc.Accordingly, those of ordinary skill will recognize that load lockprocessing can be performed on one or more load locks while waferprocessing can be performed on another load lock. Further, it can beunderstood herein that the methods and systems illustrated by FIG. 17can be performed in parallel, for example, as wafer processing 208 and222 can be performed in parallel with return of a processed wafer to thecassette, next wafer retrieval and orienting, 210-216 and 224, 200-204,respectively.

Those of ordinary skill will also recognize that although the methodsand systems presented an embodiment where during processing of aprocessed wafer, a processed wafer is returned, and a next wafer isretrieved and oriented, some methods and systems may include shorterprocessing times such that processing may not coincide completely withreturn, retrieval, and orienting. Accordingly, in some embodiments,processing may complete before return, retrieval, and orienting, 210,114, 216, while in other embodiments, processing may not complete untilafter return, retrieval, and orienting, 210, 214, 216, and thus mayindicate a delay until removal 218 and/or a measurement or other meansto indicate when processing is complete.

What has thus been described are systems and methods for handling wafersthat include retrieving a first wafer from a wafer cassette using afirst arm, transferring the first wafer from the first transfer arm to asecond arm, delivering the first wafer for processing to a processchamber using the second arm, removing the first wafer from the processchamber using the first arm, and, returning the first wafer to thecassette using the first arm.

The methods and systems described herein are not limited to a particularhardware or software configuration, and may find applicability in manycomputing or processing environments. For example, the control of thecassette interchanges, evacuation and venting, load lock valves,orienters, processing systems (e.g., platen, ion implantation, etc.),and the arms, can be implemented in hardware or software, or acombination of hardware and software. The methods and systems can beimplemented in one or more computer programs, where a computer programcan be understood to include one or more processor executableinstructions. The computer program(s) can execute on one or moreprogrammable processors, and can be stored on one or more storage mediumreadable by the processor (including volatile and non-volatile memoryand/or storage elements), one or more input devices, and/or one or moreoutput devices. The processor thus can access one or more input devicesto obtain input data, and can access one or more output devices tocommunicate output data. The input and/or output devices can include oneor more of the following: Random Access Memory (RAM), Redundant Array ofIndependent Disks (RAID), floppy drive, CD, DVD, magnetic disk, internalhard drive, external hard drive, memory stick, or other storage devicecapable of being accessed by a processor as provided herein, where suchaforementioned examples are not exhaustive, and are for illustration andnot limitation.

The computer program(s) is preferably implemented using one or more highlevel procedural or object-oriented programming languages to communicatewith a computer system; however, the program(s) can be implemented inassembly or machine language, if desired. The language can be compiledor interpreted.

As provided herein, the processor(s) can thus be embedded in one or moredevices that can be operated independently or together in a networkedenvironment, where the network can include, for example, a Local AreaNetwork (LAN), wide area network (WAN), and/or can include an intranetand/or the Internet and/or another network. The network(s) can be wiredor wireless or a combination thereof and can use one or morecommunications protocols to facilitate communications between thedifferent processors. The processors can be configured for distributedprocessing and can utilize, in some embodiments, a client-server modelas needed. Accordingly, the methods and systems can utilize multipleprocessors and/or processor devices, and the processor instructions canbe divided amongst such single or multiple processor/devices.

The device(s) or computer systems that integrate with the processor(s)can include, for example, a personal computer(s), workstation (e.g.,Sun, HP), personal digital assistant (PDA), handheld device such ascellular telephone, laptop, handheld, or another device capable of beingintegrated with a processor(s) that can operate as provided herein.Accordingly, the devices provided herein are not exhaustive and areprovided for illustration and not limitation.

References to “a processor” or “the processor” can be understood toinclude one or more processors that can communicate in a stand-aloneand/or a distributed environment(s), and can thus can be configured tocommunicate via wired or wireless communications with other processors,where such one or more processor can be configured to operate on one ormore processor-controlled devices that can be similar or differentdevices. Furthermore, references to memory, unless otherwise specified,can include one or more processor-readable and accessible memoryelements and/or components that can be internal to theprocessor-controlled device, external to the processor-controlleddevice, and can be accessed via a wired or wireless network using avariety of communications protocols, and unless otherwise specified, canbe arranged to include a combination of external and internal memorydevices, where such memory can be contiguous and/or partitioned based onthe application. Accordingly, references to a database can be understoodto include one or more memory associations, where such references caninclude commercially available database products (e.g., SQL, Informix,Oracle) and also proprietary databases, and may also include otherstructures for associating memory such as links, queues, graphs, trees,with such structures provided for illustration and not limitation.

References to a network, unless provided otherwise, can include one ormore intranets and/or the Internet.

Many additional changes in the details, materials, and arrangement ofparts, herein described and illustrated, can be made by those skilled inthe art. Accordingly, it will be understood that the following claimsare not to be limited to the embodiments disclosed herein, can includepractices otherwise than specifically described, and are to beinterpreted as broadly as allowed under the law.

1. A system for handling wafers, the system comprising: a first arm for handling wafers, a distinct second arm for handling wafers, a first cassette of wafers, and, a wafer processing system, where wafers are delivered to the processing system from the first cassette using the first arm and the second arm, and where the delivery includes, individually retrieving a first wafer from the cassette using the first arm, transferring the first wafer from the first arm to the second arm, delivering the first wafer for processing by the wafer processing system using the second arm, processing the first wafer to generate a processed wafer, while retrieving a next wafer from the cassette using the first arm, transferring the next wafer to the second arm, removing the processed wafer using the first arm and delivering the next wafer for processing using the second arm, processing the next wafer to generate a processed wafer while returning the processed wafer to the cassette, and iteratively performing the processing, transferring, removing, and processing to process the wafers in the cassette.
 2. A system according to claim 51, further including a first load lock for the first cassette.
 3. A system according to claim 51, further including an orienter for orienting the wafers before processing and transferring the wafers between the first arm and the second arm.
 4. A system according to claim 51, further including a platen for retrieving wafers from the second arm for delivering the wafers, and transferring processed wafers to the first arm for removing the processed wafers.
 5. A system for handling wafers, the system comprising: a first arm for handling wafers, a distinct second arm for handling wafers, a first cassette of wafers, and, a wafer processing system, where wafers are delivered to the processing system from the first cassette using the first arm and the second arm, and where the delivery includes, individually retrieving a first wafer from the cassette using the first arm, delivering the first wafer for processing by the wafer processing system using the first arm, returning a processed wafer to the cassette using a second arm while processing the first wafer to generate a processed wafer, retrieving a next wafer from the cassette using the second arm, removing the processed wafer using the first arm and delivering the next wafer for processing using the second arm, processing the next wafer to generate a processed wafer while returning the processed wafer to the cassette, and iteratively performing the retrieving, delivering, returning, retrieving, removing, and processing to process the wafers in the cassette.
 6. A system according to claim 55, further including a first load lock for the first cassette.
 7. A system according to claim 55, further including an orienter for orienting the wafers before processing.
 8. A system according to claim 55, further including a platen for retrieving wafers from the first and second arms for processing the wafers, and transferring processed wafers to the first and second arms for removing the processed wafers.
 9. A system according to claim 55, further including at least one carriage for moving the first and second arms relative to the cassette for returning and retrieving wafers from the cassette. 